淫羊藿苷通过上调Runx2促进踝关节骨折大鼠骨重建及抑制破骨细胞形成

Icariin Promotes Bone Reconstruction and Inhibits Osteoclast Formation in Ankle Fracture Rats Through Up-regulation of Runx2

【目的】观察淫羊藿苷对踝关节骨折大鼠的治疗作用及机制。【方法】取55只SD大鼠,建立踝关节骨折模型。将成功造模的全部50只大鼠随机分为模型组,淫羊藿苷低、中、高剂量组及阳性药组,每组10只。淫羊藿苷低、中、高剂量组分别给予腹腔注射淫羊藿苷30、60、120 mg/kg,阳性药组给予腹腔注射复方骨肽注射液0.4 mL/kg,模型组给予腹腔注射等体积生理盐水,每日1次,连续给药4周。给药结束后,进行Micro-CT活体扫描及生物力学测试,采用抗酒石酸酸性磷酸酶(TRAP)染色法检测骨痂组织破骨细胞数量,苏木素-伊红(HE)染色法观察骨痂组织病理学变化,采用Western Blot法检测骨痂组织Runt相关转录因子2(Runx2)蛋白表达量。【结果】与模型组比较,淫羊藿苷低、中、高剂量组和阳性药组干预2、4周后骨小梁数量(Tb.N)、最大载荷、刚度、骨体积分数(BV/TV)值及骨痂组织Runx2蛋白表达量升高,骨痂组织破骨细胞数量减少(P<0.05),淫羊藿苷各剂量组作用效果呈剂量依赖性;但淫羊藿苷各剂量组干预2、4周后Tb.N、最大载荷、刚度、BV/TV值及骨痂组织Runx2蛋白表达量均低于同期阳性药组,骨痂组织破骨细胞数高于阳性药组(均P<0.05)。【结论】淫羊藿苷可促进踝关节骨折创伤大鼠骨重建,抑制破骨细胞形成,提高生物力学性能,其作用机制可能与上调Runx2蛋白表达有关;但其作用效果不及复方骨肽注射液。

Objective To observe the therapeutic effect and mechanism of icariin in rats with ankle fracture.Methods Fifty SD rats were taken to establish ankle fracture models. All 50 of successfully modeled them were randomly divided into model group,icariin low-,medium-and high-dose groups and positive drug group,with10 rats in each group. Icariin low-,medium-and high-dose groups were intraperitoneally injected with 30,60,120 mg/kg of icariin, respectively, the positive drug group was intraperitoneally injected with 0.4 mL/kg of compound osteopeptide injection, and in the model group, an equal volume of normal saline was injected intraperitoneally,once a day for 4 continuous weeks. After medication,Micro-CT intravital scan was carried out,and biomechanics was tested. Tartrate-resistant acid phosphatase(TRAP)staining method was used to detect the number of osteoclasts in callus tissue,hematoxylin-eosin(HE)staining method was used to observe the changes in pathological feature of callus tissue,Western Blot was used to detect the protein expression level of Runt-related transcription factor 2(Runx2)in callus tissue. Results Compared with the model group,the values of trabecular number(Tb.N),maximum load,stiffness,bone volume/total volume(BV/TV)and the protein expression level of callus tissue Runx2 were increased,and the number of osteoclasts in callus tissue was decreased in the icariin low-,medium-and high-dose groups and the positive drug group after 2-and 4-week intervention(all P<0.05),and the effect of each dose group of icariin was dose dependent;however,in each dose groups of icariin after 2-and 4-week intervention,the Tb.N,maximal load,stiffness,BV/TV values and callus tissue Runx2protein expression level were lower,and the number of osteoclasts in callus tissue was higher than those of the positive drug group at the same time(all P<0.05). Conclusion Icariin has effects in promoting bone reconstruction,inhibiting osteoclast formation and improving biomechanical properties in ankle fracture rats,and its mechanism of action may be related to the up-regulation of Runx2 protein expression. However,its effect is not as effective as that of compound bone peptide injection.